Metals and alloys, such as, for example, iron, nickel, titanium, cobalt, and alloys based on these metals, are often used in critical engineering applications in which fine-grained microstructures, homogeneity, and/or substantially defect free compositions are advantageous or necessary. Problems such as undesired grain growth and segregation in metal and alloy castings and ingots may be detrimental to end-use applications and can significantly increase the costs associated with high quality alloy production. Conventional alloy production techniques, such as vacuum induction melting, electroslag refining, and vacuum arc remelting, may be used to reduce the amount of impurities and contaminants in alloy castings. However, in various instances, conventional cast-and-wrought alloy production processes cannot be used to produce alloys having the fine-grained microstructures, homogeneity, and/or substantially defect free compositions desired or required for various critical engineering applications.
Powder metallurgy processes can allow for the production of metals and alloys having fine-grained microstructures that cannot be achieved with cast-and-wrought alloy production processes. However, powder metallurgy processes are more complex than cast-and-wrought alloy production processes and may produce metals and alloys having relatively high levels of voids and porosity. Powder metallurgy processes also have the potential to introduce impurities and contaminants into metal and alloy products during the production, handling, and processing of the powder feed stocks used to form the products.